Puzzles, what are they good for?

[Deep One]

Question:
What do you think about puzzles like this?
Remember, that I always mean the "hard" method, but be warned to spoilers!
See this puzzles just as "examples" of design and challenge.

http://silenthill.wikia.com/wiki/Crematorium_Puzzle
http://silenthill.wikia.com/wiki/Tarot_Card_Puzzle
http://silenthill.wikia.com/wiki/Shakespeare_Anthology
http://silenthill.wikia.com/wiki/Stanley_Coleman
http://silenthill.wikia.com/wiki/Piano_Puzzle
http://silenthill.wikia.com/wiki/Coin_Puzzle

Those are cleverly designed, but too hard for me (I don't want to exit the game every 10 minutes to check the answer). Penumbra puzzles are just perfect IMO